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arXiv 1201.4398astro-ph.CO
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利用多波段光度函数测量重建已知星系群的近红外背景涨落

Reconstructing the Near-IR Background Fluctuations from known Galaxy Populations using Multiband Measurements of Luminosity Functions

Kari Helgason, Massimo Ricotti, Alexander Kashlinsky

摘要:

我们的宇宙红外背景(CIB)的波动模型所产生的已知星系人口使用233测量的紫外线,光学和近红外光度函数(LF)从各种调查跨越了广泛的红移。我们比较了文献中最佳拟合的Schechter参数,并发现了红移演化的明确迹象。给出了在z~5范围内LFs多波段演化的拟合公式,计算了观测者坐标系中红移到近红外波段的总辐射,并较好地恢复了观测到的光学和近红外星系计数。我们的经验方法,结合描述星系团的晕模型,使我们能够计算未解决的CIB的波动,并将模型与当前的测量结果进行比较。我们发现,从已知的星系人口的波动是无法解释的斯皮策/IRAC和AKARI/IRC看到的大规模CIB集群信号,并继续发散到更大的角度尺度。即使LF外推到具有陡峭的暗端斜率的暗星等,直到z=8,这也是正确的。我们还表明,消除解决的来源,逐步变暗的幅度限制,隔离CIB波动越来越高的红移。我们的经验方法表明,已知的星系人口是不负责的大部分的波动信号中看到的测量和有利于一个非常微弱的人口高度聚集的来源。

英文摘要:

We model fluctuations in the Cosmic Infrared Background (CIB) arising from known galaxy populations using 233 measured UV, optical and NIR luminosity functions (LF) from a variety of surveys spanning a wide range of redshifts. We compare best-fit Schechter parameters across the literature and find clear indication of evolution with redshift. Providing fitting formulae for the multi-band evolution of the LFs out to z~5, we calculate the total emission redshifted into the near-IR bands in the observer frame and recover the observed optical and near-IR galaxy counts to a good accuracy. Our empirical approach, in conjunction with a halo model describing the clustering of galaxies, allows us to compute the fluctuations of the unresolved CIB and compare the models to current measurements. We find that fluctuations from known galaxy populations are unable to account for the large scale CIB clustering signal seen by Spitzer/IRAC and AKARI/IRC and continue to diverge out to larger angular scales. This holds true even if the LFs are extrapolated out to faint magnitudes with a steep faint-end slope all the way to z=8. We also show that removing resolved sources to progressively fainter magnitude limits, isolates CIB fluctuations to increasingly higher redshifts. Our empirical approach suggests that known galaxy populations are not responsible for the bulk of the fluctuation signal seen in the measurements and favors a very faint population of highly clustered sources.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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